It is well known in the art to utilize a light beam as a sighting aid for weapons. An illumination source is provided that projects a narrow beam of light in a direction parallel to the weapon boresight. When the light beam and boresight are properly aligned, the bullet (or other projectile) will hit on or very close to the location of the light beam on the target. Light beam sighting aids are particularly useful at night when ordinary iron or telescopic sights are difficult to use because of low ambient and/or target illumination levels. Light beam sights for weapons are well known in the art.
Lasers are the preferred mechanism of generating light beams for sighting applications. They have comparatively high intensity and can be focused into a narrow beam with a very small divergence angle so that they produce a small, bright light spot on the target tens to hundreds of yards from the light source. Semiconductor light emitting diodes (LEDs) are well known compact light sources that are suitable. As used herein the word "laser" is intended to include any form of light source, and the words "laser sight" are intended to refer to a light emitting module or assembly that projects a beam of light having a small divergence angle suitable for alignment, sighting or pointing purposes. The term "light emitting module" is intended to include an LED or any other type of suitable light source. Light emitting modules for pointing and sighting purposes are well known in the art.
It is known in the art to attach a light emitting module to the trigger guard of a hand gun or other weapon. The battery and other electronics necessary to power an LED may be included within the module or mounted in the butt of the weapon. There are several types of prior art trigger guard mounts. A first type uses two sets of spaced-apart U-shaped clamps. Such a dual-clamp type mount generally provides reasonable stability for the laser sight because it is attached in two spaced-apart locations on the trigger guard. However, a dual-clamp type mount has the disadvantages of being bulkier and more expensive than a single-clamp type of mount.
A second type of mount uses a single U-shaped clamp. Such single-clamp mounts come in several varieties: (i) a custom fitted clamp which is machined to precisely fit a particular weapon, and (ii) a "universal" clamp which is intended to fit a wide variety of weapons. The custom fitted clamp provides reasonable stability for a laser sight but has the disadvantage of being comparatively expensive and only being suitable for the particular weapon trigger guard that it is shaped to fit. The prior art universal, single-clamp mount suffers from a number of disadvantages described below.
A significant practical problem associated with trigger guard mounted laser sights is that trigger guards are complex three-dimensional shapes with non-uniform cross-sections. A trigger guard's function is to prevent accidental discharge of the weapon by inadvertent contact with the trigger. A trigger guard must be smooth so as to not catch on holsters, pockets, trouser waist bands and other locations in which a weapon is carried ready for use. It is these requirements that dictate trigger guard design. Historically, little or no thought has been given to making trigger guards suitable for attachment of a light emitting module since such modules are a comparatively recent development. Classical trigger guard shapes are generally inconvenient for attachment of a light emitting module. A further complication is that different types of weapons have different trigger guard shapes, even guns from the same manufacturer. Thus, it has been difficult to provide a mounting fixture for attaching a laser sight to a trigger guard that is both rugged (i.e., shock and movement resistant) and adaptable to many different types of trigger guards of past, present and future weapons, i.e., a "universal" mount.
Unless custom fitted, prior art universal type, single-clamp trigger guard mounts for laser sights have generally not proved to be sufficiently rugged. It is difficult to maintain alignment of the light emitting module. The shock associated with handling and shooting the weapon is sufficient in many cases to jar the module sufficiently so that the light beam is knocked out of alignment with the weapon boresight. In order to maintain accuracy of the laser sight, it has been necessary to repeatedly remount and/or realign the light emitting module, or to have a skilled gunsmith or machinist custom fit the mount to the desired weapon. Thus, prior art single-clamp trigger guard mounts have not proved well suited for a "do-it-yourself" type of installation, especially one that is adaptable for many trigger guard shapes on different types of guns.
A further problem with prior art arrangements has been the use of electrical switches for turning the laser sight on and off which protrude from the laser sight in such a way as to sometimes interfere with drawing and replacing the weapon in a holster, pocket, waist band or other carrying place.
Thus, there continues to be a need for an improved, externally mounted laser sight for weapons (e.g., hand guns) and other purposes, and especially for a universal type mount which attaches to multiple trigger guards or other structures of complex shape using a single clamp, and further for sights that have a low profile integral on/off switch.